Efficacy of imidacloprid (Confidor 200SL) and improved cultural practices in the control of the green date palm pit scale insect (Asterolecanium phoenicis Rao.) (Palmapsis phoenicis) (Homoptera: Asterolecaniidae) in Northern Sudan

Abstract

Experiments were undertaken in Elgaba scheme for two seasons (1999/2000 and 2000/2001) to evaluate the efficacy of imidacloprid (as Confidor 200SL) as part of a technical cultural practices package (earthing, pruning and regular irrigation) in the control of the date palm green pit scale insect Asterolecanium phoenicis (Rao). Four doses of Confidor 200SL (15, 20, 25 and 35 ml/palm) were compared with standard insecticide carbofuran (Furadan 5G (60g/palm) and untreated control. A Completely Randomized Design with six replicates (one palm = replicate) was used. The insects (all developing stages) were counted per cm2 per leaflet. Eight leaflets, from each palm, were inspected biweekly. Date yield and quality were determined at harvest. Residue analysis was carried out twice on dates, soil and plants intercropped with date palms. Results indicated that percentage mortality of both adults and immature stages were significantly higher in the insecticides treatments than in untreated control after two weeks. All insecticides lost their efficacy after twelfth weeks. The efficacy of the treatments followed the order; Confidor (35 ml/palm), Furadan 5G (60 g/palm) and Confidor (25 ml/palm). No detectable residues of imidaclprid were found on dates, soil or intercropped plants even at the high dose of Confidor 200SL (35 ml/palm) used. Date palm treated with Confidor (25 ml/palm), developed normally and the dates reached maturity (ripening) normally compared to the untreated control. The percentage of unripe date (1.7) was significantly (p = 0.01) lower than in the untreated control (27.33). Confidor checked the activity of termites and many other pests. Partial budget analysis indicated the profitability of this package as estimated by the marginal rate of return of 29.8 and 201% over one and three year’s period, respectively. Key words: Sudan, date palms, Aesterolecanium phoeniccis, control measures, imidacloprid.